1. Field of the Invention
The present invention relates to copying machines having a color developing function, outline image forming function and character writing function.
2. Description of the Prior Art
Many copying machines have various functions in addition to the basic function. For example, copying machines are available which are equipped with two developing units with different toner colors and have a two-color copying function for giving copies in the two colors by the touch of a key. Also available are those wherein the photosensitive drum is provided with character writing means including a shutter and writing head (LED array) and which have the function of writing data in characters on copies (e.g. Japanese Laid-Open Patent Application No. 60-130782). Further known are those incorporating a charger between the point of exposure of the photosensitive drum and the developing unit for giving the copying machine the function of forming an outline image of a pattern (e.g. U.S. Pat. No. 745,437).
When such additional functions are to be provided, the devices for performing the functions (such as the second of the developing units, scorotron charger, LED array and the like) must be arranged around the photosensitive drum. In this case, if all of these devices are to be incorporated in the machine as standard equipment, the required space is not available around the photosensitive drum, or the machine has the drawback of being costly.